Acoustic frequency detection and wave based systems are known in manufacturing and oil industries for imaging and non-destructive evaluation (NDE) of materials. Such systems may involve the propagation of energy through solids, liquids, and gases as waves; typically a pulse of energy is applied to an object to be imaged and reflected waves of the pulse are detected and processed for imaging. The spatial relationship and amplitude of the reflected waves provide information as to the location and nature of structures that reflected the acoustic energy in the object being analyzed.
NDE of objects for detection of contraband and/or explosives is known according to some specific approaches. Such NDE approaches may include acoustic frequency detection or vision-based systems such as infrared, Millimeter Wave (MMW), multispectral, hyperspectral, infrared, X-ray, or imaging radar output. However, such systems have significant limitations. For example, known ultrasound based systems employ pulses, the generator of which must be physically applied to an object through surface contact, preferably through a medium such as gel or the like. Additionally, ultrasound is less effective at penetrating heavy clothing than other systems, such as radar.
Likewise, other systems, such as MMW and imaging radar systems are similarly limited in penetration of certain materials. Separately, infrared sensing systems can be impractical due to very small temperature contrasts that may exist between hidden contraband and outer layers of covering material of a given container. Although X-ray and magnetic portal detector systems have proven much more effective at detecting both metallic and non-metallic concealed weapons than some of the above systems, such “portal” detection technologies are inherently limited by the inability to operate in a mobile fashion, and at any rate, do not necessarily identify certain types of explosives and most narcotics.
In each of the above cases, known systems do not provide for mobile applications, nor do they detect disparate categories of contraband, whether narcotics, smuggled gems, illicit quantities of cash, various chemical categories of explosives, or biological agents. Accordingly, known approaches are limited in terms of protective applications and mobile field usage.